805 research outputs found
Nucleus polarizability contribution to the hydrogen-deuterium isotope shift
The correction to the hydrogen-deuterium isotope shift due to the proton and
deuteron polarizability is evaluated on the basis of modern experimental data
on the structure functions of inelastic lepton-nucleus scattering. The
numerical value of this contribution is equal 63\pm 12 Hz.Comment: 5 page
Relativistic Effects in S-Wave Quarkonium Decay
The decay widths of S-wave quarkonia (\etc,\etb\to \gg{~~and~~}
\J,\U\to\ee) are calculated on the basis of a quasipotential approach. The
nontrivial dependence on relative quark motion of decay amplitude is taken into
consideration via quarkonium wave function. It is shown that relativistic
corrections may be large (10-50 %) and comparable with QCD corrections.Comment: 10 pages, no figure
Hyperfine structure of the ground state muonic He-3 atom
On the basis of the perturbation theory in the fine structure constant
and the ratio of the electron to muon masses we calculate one-loop
vacuum polarization and electron vertex corrections and the nuclear structure
corrections to the hyperfine splitting of the ground state of muonic helium
atom . We obtain total result for the ground state hyperfine
splitting MHz which improves the previous
calculation of Lakdawala and Mohr due to the account of new corrections of
orders and . The remaining difference between our
theoretical result and experimental value of the hyperfine splitting lies in
the range of theoretical and experimental errors and requires the subsequent
investigation of higher order corrections.Comment: Talk on poster section of XXIV spectroscopy congress, 28 February-5
March 2010, Moscow-Troitsk, Russia, 21 pages, LaTeX, 8 figure
Muonic hydrogen ground state hyperfine splitting
Corrections of orders alpha^5, alpha^6 are calculated in the hyperfine
splitting of the muonic hydrogen ground state. The nuclear structure effects
are taken into account in the one- and two-loop Feynman amplitudes by means of
the proton electromagnetic form factors. The modification of the hyperfine
splitting part of the Breit potential due to the electron vacuum polarization
is considered. Total numerical value of the 1S state hyperfine splitting
182.638 meV in the (mu p) can play the role of proper estimation for the
corresponding experiment with the accuracy 30 ppm.Comment: 18 pages, Talk presented at the 11th Lomonosov Conference on
Elementary Particle Physics, Moscow State University, August 200
Theory of muonic hydrogen - muonic deuterium isotope shift
We calculate the corrections of orders alpha^3, alpha^4 and alpha^5 to the
Lamb shift of the 1S and 2S energy levels of muonic hydrogen (mu p) and muonic
deuterium (mu d). The nuclear structure effects are taken into account in terms
of the proton r_p and deuteron r_d charge radii for the one-photon interaction
and by means of the proton and deuteron electromagnetic form factors in the
case of one-loop amplitudes. The obtained numerical value of the isotope shift
(mu d) - (mu p) for the splitting (1S-2S) 101003.3495 meV can be considered as
a reliable estimation for corresponding experiment with the accuracy 10^{-6}.
The fine structure interval E(1S)-8E(2S) in muonic hydrogen and muonic
deuterium are calculated.Comment: 22 pages, 7 figure
One-loop corrections of order (Z alpha)^6m_1/m_2, (Z alpha)^7 to the muonium fine structure
The corrections of order (Z alpha)^6m_1/m_2 and (Z alpha)^7 from one-loop
two-photon exchange diagrams to the energy spectra of the hydrogenic atoms are
calculated with the help of the Taylor expansion of corresponding integrands.
The method of averaging the quasipotential over the wave functions in the
d-dimensional coordinate space is formulated. The numerical values of the
obtained contributions to the fine structure of muonium, hydrogen and
positronium are presented.Comment: Talk given at the XVIth International Workshop High-Energy Physics
and Quantum Field Theory (QFTHEP2001), Moscow, Russia, 6-12 Sep 2001, 12
pages, REVTE
Proton polarizability and the Lamb shift in muonic hydrogen
The proton structure and proton polarizability corrections to the Lamb shift
of electronic hydrogen and muonic hydrogen were evaluated on the basis of
modern experimental data on deep inelastic structure functions. Numerical value
of proton polarizability contribution to (2P-2S) Lamb shift is equal to 4.4
GHz.Comment: 8 pages, LaTeX2.09, 2 figures, uses linedraw.st
CLINICAL PRESENTATIONS OF ARTERIAL HYPERTENSION DEPENDING ON THE QTC INTERVAL DURATION OF ECG
The relationship between the duration of the complex QTc ECG and clinical signs of arterial hypertension (AH) in 54 patients (16 men and 38 women) 1-3 degree and I-III stage, mean age 58 ± 18 years, was investigated. 3 classes of QT interval duration were allocated: classified shortened ( 320 ms and 440 ms). The binomial distribution of frequencies of studied parameters in classes of the QTc interval for alternative criteria was determined. The duration of the QTc interval in the sampling was 350 ms – 490 ms. The proportion of the normal range (> 320 ms and 440 ms) – 0.15. The probability of occurrence of QTc prolongation ECG increased in elderly patients, obesity, abusing of alcohol, mild and moderate degree and stage II AH, diabetes mellitus, atherosclerotic cardiosclerosis, stable angina functional class (FC) II, HF FC III and II A stage. Dependencies of the elongated QTc of ECG from the sex of the patients have not been established
New analysis of semileptonic B decays in the relativistic quark model
We present the new analysis of the semileptonic B decays in the framework of
the relativistic quark model based on the quasipotential approach. Decays both
to heavy D^{(*)} and light \pi(\rho) mesons are considered. All relativistic
effects are systematically taken into account including contributions of the
negative-energy states and the wave function transformation from the rest to
moving reference frame. For heavy-to-heavy transitions the heavy quark
expansion is applied. Leading and subleading Isgur-Wise functions are
determined as the overlap integrals of initial and final meson wave functions.
For heavy-to-light transitions the explicit relativistic expressions are used
to determine the dependence of the form factors on the momentum transfer
squared. Such treatment significantly reduces theoretical uncertainties and
increases reliability of obtained predictions. All results for form factors,
partial and total decay rates agree well with recent experimental data and
unquenched lattice calculations. From this comparison we find the following
values of the Cabibbo-Kobayashi-Maskawa matrix elements:
|V_{cb}|=(3.85\pm0.15\pm 0.20)*10^{-2} and
|V_{ub}|=(3.82\pm0.20\pm0.20)*10^{-3}, where the first error is experimental
and the second one is theoretical.Comment: 25 pages, 11 figure
Hyperfine Structure of S-States in Muonic Helium Ion
Corrections of orders alpha^5 and alpha^6 are calculated in the hyperfine
splittings of 1S and 2S - energy levels in the ion of muonic helium. The
electron vacuum polarization effects, the nuclear structure corrections and
recoil corrections are taken into account. The obtained numerical values of the
hyperfine splittings -1334.56 meV (1S state), -166.62 meV (2S state) can be
considered as a reliable estimate for the comparison with the future
experimental data. The hyperfine splitting interval Delta_{12}=(8 Delta
E^{hfs}(2S)- Delta E^{hfs}(1S)) = 1.64 meV can be used for the check of quantum
electrodynamics.Comment: 14 pages, 5 figure
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